Stent graft delivery system

ABSTRACT

A stent graft delivery system including a stent graft cover, a screw gear, and a handle assembly. The handle assembly includes an external slider, a T-tube, and a Y-adapter. The external slider is configured to rotate about the screw gear. The T-tube and the Y-adapter collectively form a hub configured to slide linearly along the screw gear as the external slider rotates. The T-tube defines a main lumen port extending therethrough and is configured to receive the stent graft cover and a main lumen. The Y-adapter defines a secondary lumen port and is configured to receive a secondary lumen.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No. 16/828,644 filed Mar. 24, 2020, the disclosure of which is hereby incorporated in its entirety by reference herein.

TECHNICAL FIELD

The present disclosure relates to a stent graft delivery system including a T-tube and a Y-adapter collectively forming a hub configured to slide linearly along a screw gear as an external slider rotates.

BACKGROUND

The use of endovascular procedures has been established as a minimally invasive technique to deliver a variety of clinical treatments in a patient's vasculature. A stent graft is an implantable device made of a tube-shaped surgical graft covering and an expanding or self-expanding frame. The stent graft is placed inside a blood vessel to bridge, for example, an aneurismal, dissected, or other diseased segment of the blood vessel, and, thereby, exclude the hemodynamic pressures of blood flow from the diseased segment of the blood vessel.

Depending on the region of the aorta involved, the aneurysm may extend into areas having vessel bifurcations or segments of the aorta from which smaller “branch” arteries extend. For example, thoracic aortic aneurysms can include aneurysms present in the ascending thoracic aorta, the aortic arch, and/or branch arteries that emanate therefrom, such as subclavian or left or right common carotid arteries. In some cases, a branched stent graft can be used to treat such aneurysms. For example, a main stent graft can be deployed in the main vessel (e.g., aortic arch), and a supplemental, secondary stent graft can be deployed in the branched artery (e.g., left subclavian).

SUMMARY

According to one embodiment, a stent graft delivery system is disclosed. The stent graft delivery system includes a stent graft cover, a screw gear, and a handle assembly. The handle assembly includes an external slider, a T-tube, and a Y-adapter. The external slider is configured to rotate about the screw gear. The T-tube and the Y-adapter collectively form a hub configured to slide linearly along the screw gear as the external slider rotates. The T-tube defines a main lumen port extending therethrough and is configured to receive the stent graft cover and a main lumen. The Y-adapter defines a secondary lumen port and is configured to receive a secondary lumen.

In another embodiment, a stent graft delivery system is disclosed. The stent graft delivery system includes a stent graft cover, a screw gear, and a handle assembly. The handle assembly includes an external slider, a T-tube, and a Y-adapter. The external slider is configured to rotate about the screw gear. The T-tube is a separate component from the Y-adapter and is connected to the Y-adapter. The T-tube and the Y-adapter collectively form a hub configured to slide linearly along the screw gear as the external slider rotates. The T-tube defines a main lumen port extending therethrough and is configured to receive the stent graft cover and a main lumen. The Y-adapter defines a secondary lumen port and is configured to receive a secondary lumen.

In yet another embodiment, a method for delivering a stent graft to a blood vessel is disclosed. The method includes inserting main and secondary guidewires into the blood vessel. The method further includes inserting a stent graft cover over the main guidewire and a secondary lumen over the secondary guidewire. The method further includes loading the stent graft through a T-tube while the secondary lumen extends through an opening in a wall of the stent graft. The T-tube is a separate component from a Y-adapter and is connected to the Y-adapter. The method further includes withdrawing the stent graft cover to deliver the stent graft to the blood vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic side view of an endoluminal stent graft, according to one embodiment.

FIG. 2 is a schematic side view of the stent graft of FIG. 1 deployed at a target location within a blood vessel, according to an embodiment.

FIG. 3 is a schematic illustration of a stent graft delivery system, according to one embodiment.

FIG. 4 is a schematic illustration of a handle region of the stent graft delivery system of FIG. 3, according to one embodiment.

FIG. 5 is a cross-sectional view of the handle region of FIG. 4 about one half of a multi-piece screw gear, according to one embodiment.

FIG. 6 is a front perspective view of a portion of the handle region, according to one embodiment.

FIG. 7 is a cross-sectional view of a handle region of a stent graft delivery system according to another embodiment.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.

Directional terms used herein are made with reference to the views and orientations shown in the exemplary figures. A central axis is shown in the figures and described below. Terms such as “outer” and “inner” are relative to the central axis. For example, an “outer” surface means that the surfaces faces away from the central axis, or is outboard of another “inner” surface. Terms such as “radial,” “diameter,” “circumference,” etc. also are relative to the central axis. The terms “front,” “rear,” “upper” and “lower” designate directions in the drawings to which reference is made.

Unless otherwise indicated, for the delivery system the terms “distal” and “proximal” are used in the following description with respect to a position or direction relative to a treating clinician. “Distal” and “distally” are positions distant from or in a direction away from the clinician, and “proximal” and “proximally” are positions near or in a direction toward the clinician. For the stent-graft prosthesis, “proximal” is the portion nearer the heart by way of blood flow path while “distal” is the portion of the stent-graft further from the heart by way of blood flow path.

The following detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Although the description is in the context of treatment of blood vessels such as the aorta, coronary, carotid and renal arteries, the invention may also be used in any other body passageways where it is deemed useful.

FIG. 1 shows a stent graft 100 configured for placement in a blood vessel. FIG. 2 shows the stent graft 100 deployed in a blood vessel 200 for treatment of an aneurysm 202 of the vessel 200. In the illustrated embodiment, the blood vessel 200 is the aorta, but it should be understood that teachings herein can apply to other blood vessels. Referring to FIGS. 1 and 2, the stent graft 100 can be self-expanding, in that it includes structures that are shaped or formed from a material that can be provided with a mechanical memory to return the structure from a compressed or constricted delivery configuration to an expanded deployed configuration. In this embodiment, the stent graft 100 includes two main components: a tubular graft 102 (also referred to as a body), and one or more stents 104 for supporting and expanding the graft 102. The graft 102 may be formed from any suitable graft material, for example and not limited to, a low-porosity woven or knit polyester, DACRON material, expanded polytetrafluoroethylene, polyurethane, silicone, or other suitable materials. In another embodiment, the graft material is a natural material such as pericardium or another membranous tissue such as intestinal submucosa. The stents 104 are radially-compressible and expandable, and are coupled (e.g., via stitching) to the material of the graft 102 for supporting the graft 102. The stents 104 are operable to self-expand into apposition with the interior wall of the aorta 200. Each stent 104 is constructed from a self-expanding or spring material, such as but not limited to nickel-titanium alloy (Nitinol), stainless steel, a pseudo-elastic metal such as a nickel titanium alloy or nitinol, various polymers, or a so-called super alloy, which may have a base metal of nickel, cobalt, chromium, or other metal, or other suitable material. The stents 104 may be a sinusoidal patterned ring including a plurality of crowns 106 or bends and a plurality of struts 108 or straight segments with each crown 106 being formed between a pair of opposing struts 108.

Stent graft 100 includes a proximal end 110, and a distal end 112, and a body 114 therebetween. The proximal end 110 may have a proximal stent 116, and the distal end 112 may have a distal stent 118. The proximal stent 116 and distal stent 118 may extend outside of the graft material 102, as shown, and may also be generally described as anchor stents or crown stents, configured to anchor to the inner walls of the vessel 200.

Along the body 114 of the stent graft is a mobile external coupling 120. The mobile external coupling 120 is disposed on an outside surface of stent graft 100 corresponding to an opening in graft material 102. The mobile external coupling 120 is generally frustoconical-shaped, or volcano-shaped with sloped side walls 122 leading to an open top 124. The mobile external coupling includes graft material 126 that can correspond or match to the graft material 102 of the body 114, although the graft material 126 can be a separate piece of graft material attached to the graft material 102. A circumferential stent or annular stent 128 may be coupled to the graft material 126 around the top 124 of the mobile external coupling 120. Also, the stent 128 may be formed of similar material as the stents 104 of the main body of the stent graft 100. As shown, the stent 128 may have a zig-zag or sinusoidal configuration around the top 124 of the mobile external coupling 120. Additional description of the mobile external coupling 120 may be found in U.S. Pat. No. 9,839,542, which is hereby incorporated by reference in its entirety. U.S. Pat. No. 9,839,542 also includes examples of dual guidewire delivery systems. Aspects of the devices, delivery systems, and/or deployment methods of U.S. Pat. No. 9,839,542 may be combined with those of the present disclosure.

FIG. 2 illustrates a schematic of the aorta 200, with several branches of the aorta shown, namely the brachiocephalic artery 204, the left common carotid artery 206, and the left subclavian artery 208. As shown in FIG. 2, the placement of the stent graft 100 is such that the mobile external coupling 120 aligns with one of the branched vessels, in this case the left subclavian artery 208 for deployment of a secondary stent graft (not shown) in the subclavian artery 208. In other embodiments, the stent graft 100 is designed such that the mobile external coupling 120 is located more toward the proximal end 110 such that it can be configured for alignment with either the left common carotid artery 206 or the brachiocephalic artery 204; the placement of the mobile external coupling 120 is merely exemplary.

A primary guidewire 130 may be utilized for tracking the stent graft 100 along to the appropriate deployment site. A secondary guidewire 210 may be utilized for tracking of a secondary stent graft (not shown). The secondary guidewire 210 extends through the opening of the mobile external coupling 120, such that the secondary stent graft may be tracked to the location of the mobile external coupling 120 for attachment thereto. The stent grafts may be delivered using a stent graft delivery system, embodiments of which are explained further below.

During a surgical procedure, the stent graft delivery system may be utilized to track along both guidewires, in which the delivery system includes a respective lumen that tracks along one of the guidewires 130, 210. Deployment of the stent graft 100 may occur once situated in the proper location within the vessel 200. However, prior to deployment of the stent graft 100, the surgical technician may be forced to retract the lumen that tracks along the secondary guidewire 210. Doing so removes that lumen so as to not interfere with the deployment of the main stent graft 100. This process can serve as a major interruption in the surgical procedure, forcing the surgical technician to reach all the way to the rear of the delivery system to withdraw the lumen from its branched lumen port, a location quite removed from the handles of the stent graft delivery system.

According to various embodiments described herein, the stent graft delivery system is provided with a branched lumen port extending in a transverse direction from a handle of the delivery system. This allows the surgical technician to withdraw the lumen surrounding the secondary guidewire 210 from a location adjacent the handle of the delivery system without having to pull the second guidewire lumen separately. For example, as will be explained in embodiments below, the branched lumen port can be attached directly to the graft cover hub of the delivery system, located within the handle of the delivery system. Simultaneous retraction of a stent graft cover and a secondary guidewire lumen is therefore enabled.

FIG. 3 shows a branched stent graft delivery system 300, according to one embodiment. The branched stent graft delivery system 300 extends between a proximal end 302 and a distal end 304. The names “proximal end” and “distal end” are not intended to be limiting, as the clinician may, during a procedure, be located closer to the distal end 304 than the proximal end 302 as the handle (explained below) is located as such. Therefore, the proximal end and the distal end may be referred to as a “first end” and a “second end,” respectively.

A threaded screw gear 306 extends along an axis between the proximal end 302 and the distal end 304. The threaded screw gear may be a multi-part shell configured to connect together to make a tubular screw gear. In one embodiment, the screw gear 306 is two half-shells configured to connect (e.g., snap or assemble) together. As will be explained below, once assembled, a groove or slot extends along the longitudinal axis thereof, between the two half-shells. FIG. 5 (described in more detail below) shows one half-shell of the screw gear 306.

A handle assembly 308 is provided for grip by the clinician. The handle assembly 308 may include two separable portions, namely a front grip 310 and an external slider 312. The front grip 310 may be fixed relative to the screw gear 306, and the external slider 312 may rotate about a threaded outer surface of the screw gear 306 to move linearly along the screw gear 306. For example, during deployment of a stent graft (such as the stent graft 100 disclosed above), the external slider 312 is rotated to move toward the proximal end 302. Since the external slider 312 is operatively coupled to a stent graft cover (e.g., a sheath or lumen) surrounding the stent graft 100, the sheath or lumen is retracted with the linear movement of the external slider 312, thus allowing the stent graft 100 to expand.

While the screw gear 306 is illustrated and described herein as having a threaded outer surface, it should be understood that in other embodiments, the screw gear is not threaded, and the external slider 312 can slide linearly along the screw gear.

The stent graft delivery system 300 also includes an access port 314. The access port 314 provides an opening for insertion of a secondary guidewire lumen, or branching lumen, for surrounding a secondary guidewire (such as the secondary guidewire 210 disclosed above).

Various embodiments described herein disclose examples of placements and structures of the access port relative to the handle assembly. For example, the access port 314 can be a direct extension of a stent graft cover hub that retracts the stent graft cover and the branching lumen as the external slider 312 is rotated. Such placement and structure maintains the position of the access port 314 adjacent to the clinician's hand, enabling the clinician to remove the branching lumen during operation as the main stent graft is deployed, without an additional step of reaching all the way back to the proximal end 302 to remove the branching lumen prior to deployment.

FIGS. 4-6 provide additional views of the handle assembly 308 and the access port 314. The handle assembly 308 is coupled to or about a sheath component 316, which may be the stent graft cover. The sheath component 316 is an elongate tubular member defining a lumen from a proximal end to a distal end thereof. The sheath component 316 may be formed from a plurality of different materials or combination of materials; in one embodiment, the sheath component 316 is formed with a composite material having a braided layer of polyether block amide, such as PEBAX®, that is sandwiched between layers of polyamide, such as VESTAMID®.

The sheath component 316 can be sized, inter alia, to receive a medical device, which may be a stent graft, a branched stent graft described herein, or other interventional device. According to embodiments described herein, the sheath component 316 surrounds a primary lumen or main lumen 318, and a secondary lumen or branched lumen 320, which may be a tube. The main lumen 318 may be a hollow tube, which may be rigid, and may also be referred to as a hypotube. The sheath 316 can track along the main guidewire 130 and is operatively connected to the external slider 312 such that rotation of the external slider 312 can retract the sheath 316, allowing expansion and deployment of the stent graft. Meanwhile, the main lumen 318 may remain rigidly fixed relative to the handle such that it does not move relative to the handle during operation. The branched lumen 320 provides a guide to track along the secondary guidewire 210.

With particular reference to the cross-sectional view of FIG. 5, within the external slider 312 is a graft cover T-tube 322. The graft cover T-tube 322 can also be referred to as a graft hub, a hub, a central hub, a handle hub, or the like. The graft cover T-tube 322 is a multi-lumen port, having a first port 324 (or main lumen port) configured to receive the main lumen 318, and a second port 326 (or branched lumen port) configured to receive the branched lumen 320. The graft cover T-tube 322 may be overmolded or otherwise directly attached to the sheath 316 such that operation of the handle to retract the graft cover T-tube 322 correspondingly retracts the sheath 316 to expose the stent graft, allowing it to expand. Both ports 324, 326 are located at a proximal end of the graft cover T-tube 322. The graft cover T-tube is generally T-shaped, with one or more wings 328 extending radially outwardly therefrom. The wings 328 provide a location of contact or force, such that as the external slider 312 is rotated about the screw gear 306, the T-tube is forced to move linearly along the central axis of the screw gear 306. For example, in one embodiment, the wings 328 have an external surface (e.g., facing radially outwardly) that is in rotational connection (indirectly or directly) with an internal surface of the external slider 312.

With the graft cover T-tube 322 being a multi-port hub, both the main lumen 318 and branched lumen 320 continue to be located at the external slider 312 during the endovascular procedure. This keeps and maintains the access port 314 and branched lumen 320 within adjacent, proximate reach of the surgical clinician. Prior to deployment of the stent graft 100, the clinician may have to assure the branched lumen 320 is retracted so as to not interfere with the deployment. By locating the access port 314 and branched lumen 320 at the graft cover T-tube 322, this eliminates the need for the clinician to divert his/her attention and pull the branched lumen 320 prior to deployment of the stent graft 100 because the branched lumen 320 is attached to the graft cover T-tube 322 and will retract as the handle 312 is operated to retract the main lumen 318. The branched lumen 320 may be directly bonded to the T-tube 322 or port 326, for example, by overmolding, an adhesive, or other methods. It may also be attached via an interference or friction fit, such that when the handle is rotated the branch lumen 320 is retracted along with the T-tube 322. Additional structure of the graft cover T-tube 322 and its surrounding structure is provided below, according to embodiments.

The second port 326 may extend from the main body of the graft cover T-tube 322 at an acute angle relative to the longitudinal axis of the delivery system, as can be seen in FIGS. 3-6. The angle may be within a range between 30 and 60 degrees, and in some particular embodiments, is between 35 and 45 degrees, and more particularly, roughly 40 degrees. It can thus be said that the second port 326 is formed as a Y-adapter for the secondary guidewire 210 and associated lumen 320. As can be seen in FIG. 5, a proximal end of the external slider 312 may include a central opening 313, and the second port 326 may extend through the central opening 313 at the acute angle. The second port 326 or Y-adapter can be co-molded or otherwise formed unitarily with the main body of the graft cover T-tube 322. FIG. 7, described below, illustrates another embodiment in which the second port 326 and Y-adapter is separate from the main body of the graft cover T-tube, but nonetheless retracts with operation of the external slider.

While not shown in the views of FIGS. 3-6, the screw gear 306 may be a two-part shell with a gap or slot running down the length thereof (e.g., in the longitudinal direction). The second port 326 or Y-adapter portion of the graft cover T-tube 322 extends through this gap, and can thus slide through the screw gear 306 as the external slider 312 is rotated about the screw gear 306.

The handle assembly 308 may also include a quick-release trigger 330. Further retraction of external slider 312 may be done more quickly than the initial controlled (rotational) retraction by pressing trigger 330 and sliding external slider 312 in the longitudinal axis of the delivery system.

As can be seen particularly in FIG. 5, in operation, the front grip 310 remains fixed to the screw gear 306, while the external slider 312 can move along the longitudinal direction of the delivery system, away from the front grip 310 to deploy the stent graft 100. To begin deployment of the stent graft (such as stent graft 100), the clinician rotates the external slider 312. This moves the external slider 312 away from the front grip 310. This also correspondingly moves the components housed within the external slider 312 (e.g., graft cover T-tube 322, etc.) away from the front grip 310. This retracts the sheath or stent graft cover 316, to allow the stent graft to deploy, while simultaneously retracting the secondary lumen 320. To finalize deployment, the clinician can utilize the trigger 330 to more quickly slide the external slider 312 (and components housed therein) away from the front grip 310.

FIG. 7 illustrates a portion of a handle assembly 400 according to another embodiment for use with a stent graft delivery system. In this embodiment, the Y-adapter is separate from the T-tube, yet both slide linearly as the handle assembly is operated to retract both main and secondary lumens during deployment of the stent graft.

Referring to FIG. 7, the handle assembly 400 includes an external slider 402 that, like previous embodiments, can rotate about a screw gear 404. A graft cover T-tube 406 is located within the external slider 402, and moves linearly along the screw gear 404 as the slider rotates. The graft cover T-tube 406 includes a main port 408 sized and configured to receive a main lumen 410. Rotation of the external slider 402 can move the graft cover T-tube 406 linearly along the screw gear 404, which correspondingly retracts the stent graft cover to deploy the stent graft, as in previous embodiments.

According to this embodiment, the Y-adapter, or secondary port 412 is separately attached to the graft cover T-tube 406. It can therefore be said that the secondary port 412 and the connected graft cover T-tube 406 collectively make up the graft cover hub or central hub. The secondary port 412 is sized and configured to receive and support a secondary lumen 414 that can track along a secondary guidewire, as in previous embodiments. A distal end of the secondary port 412 is connected to a proximal end of the primary port 408 at a connection point, or seal 416. The seal 416 is flexible, and is disposed radially outward from the secondary lumen 414. In other words, the secondary lumen 414 extends between the graft cover T-tube 406 and the main lumen 410.

The embodiment shown in FIG. 7 may facilitate pull-loading of the stent graft device through the T-tube 406 while still having the secondary lumen 414 extending through a mobile external coupling or other opening in the wall of the stent graft to be loaded. This may be because in a pull-loading process, there would be no way for the secondary lumen 414 to extend through the opening in the stent graft with an integral T-tube and secondary port (an integral T-tube may be used for push-loading). In the embodiment of FIG. 7, the graft may have the secondary lumen pre-tracked through the opening and may be pull-loaded into the delivery system. The secondary lumen 414 may then be extended through the secondary port 412, which may then be attached to the T-tube 406.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, to the extent any embodiments are described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics, these embodiments are not outside the scope of the disclosure and can be desirable for particular applications. 

What is claimed is:
 1. A stent graft delivery system comprising: a stent graft cover; a screw gear; and a handle assembly including an external slider, a T-tube, and a Y-adapter, the external slider configured to rotate about the screw gear, the T-tube and the Y-adapter collectively form a hub configured to slide linearly along the screw gear as the external slider rotates, the T-tube defines a main lumen port extending therethrough and is configured to receive the stent graft cover and a main lumen, and the Y-adapter defines a secondary lumen port and is configured to receive a secondary lumen.
 2. The stent graft delivery system of claim 1, wherein the hub is configured to slide linearly to retract both of the main and secondary lumens as the external slider rotates.
 3. The stent graft delivery system of claim 1, wherein the Y-adapter is connected to the T-tube at a seal.
 4. The stent graft delivery system of claim 3, wherein the seal is a flexible seal.
 5. The stent graft delivery system of claim 3, wherein the seal is disposed radially outward the secondary lumen.
 6. The stent graft delivery system of claim 3, wherein the secondary lumen extends between the main lumen and the seal.
 7. The stent graft delivery system of claim 3, wherein the secondary lumen extends between the T-tube and the main lumen.
 8. The stent graft delivery system of claim 1, wherein the Y-adapter includes a proximal end and a distal end, the T-tube includes a proximal end and a distal end, and the distal end of the Y-adapter is connected to the proximal end of the T-tube.
 9. A stent graft delivery system comprising: a stent graft cover; a screw gear; and a handle assembly including an external slider, a T-tube, and a Y-adapter, the external slider configured to rotate about the screw gear, the T-tube is a separate component from the Y-adapter and is connected to the Y-adapter, the T-tube and the Y-adapter collectively form a hub configured to slide linearly along the screw gear as the external slider rotates, the T-tube defines a main lumen port extending therethrough and is configured to receive the stent graft cover and a main lumen, and the Y-adapter defines a secondary lumen port and is configured to receive a secondary lumen.
 10. The stent graft delivery system of claim 9, wherein the hub is configured to slide linearly to retract both of the main and secondary lumens as the external slider rotates.
 11. The stent graft delivery system of claim 9, wherein the Y-adapter is connected to the T-tube at a seal.
 12. The stent graft delivery system of claim 11, wherein the seal is a flexible seal.
 13. The stent graft delivery system of claim 11, wherein the seal is disposed radially outward the secondary lumen.
 14. The stent graft delivery system of claim 11, wherein the secondary lumen extends between the main lumen and the seal.
 15. The stent graft delivery system of claim 11, wherein the secondary lumen extends between the T-tube and the main lumen.
 16. The stent graft delivery system of claim 9, wherein the Y-adapter includes a proximal end and a distal end, the T-tube includes a proximal end and a distal end, and the distal end of the Y-adapter is connected to the proximal end of the T-tube.
 17. A method for delivering a stent graft to a blood vessel, the method comprising: inserting a main guidewire into the blood vessel; inserting a secondary guidewire into the blood vessel; inserting a stent graft cover over the main guidewire; inserting a secondary lumen over the secondary guidewire; loading the stent graft through a T-tube while the secondary lumen extends through an opening in a wall of the stent graft, the T-tube is a separate component from a Y-adapter and is connected to the Y-adapter; and withdrawing the stent graft cover to deliver the stent graft to the blood vessel.
 18. The method of claim 17, wherein the loading step includes pull-loading the stent graft through the T-tube while the secondary lumen extends through the opening in the wall of the stent graft.
 19. The method of claim 17, wherein the opening is a mobile external coupling.
 20. The method of claim 17, wherein the T-tube receives a main lumen and the Y-adapter receives a secondary lumen, and further comprising retracting both of the main and secondary lumens as an external slider rotates. 